Cover for a cage for laboratory animals, and cage for laboratory animals including said cover

The present application is a continuation of U.S. patent application Ser. No. 16/032,987, filed Jul. 11, 2018, which claims priority to Italian Patent Application No. 102017000078916 filed Jul. 13, 2017, the entirety of the disclosure of which is expressly incorporated herein by reference.

Not Applicable

The present invention belongs to the field of housing laboratory animals. In particular, the present invention relates to a cage for housing laboratory animals. In detail, the present solution relates to a cage of the kind identified above, provided with a novel opening and access system. In greater detail, the novel system according to the present invention relates to handling and positioning the cover of a cage of the aforesaid type.

To date, the use is widespread of cages for housing laboratory animals such as for example, small rodents or the like, the cages having variable sizes and shapes according to the number of animals to be housed and the conditions to be ensured to the animals themselves. For example, the use is widespread of “ventilated” cages, namely of cages in which a flow of forced air taken from a main circuit is caused to circulate.

However, in addition to specificities provided according to needs and/or circumstances, the cages of known type or at least those most commonly used essentially comprise a tray designed to contain the litter and a cover (also called top hereinafter); moreover, there is usually housed a third component in the tray, the trough, which is designed to contain the food in accessible position for the animals and so that the food does not come into contact with the litter. Finally, a bottle with the drinking water may be prepared inside the cage or also outside and resting on the cover.

The cover or top is positioned above the tray (and possibly fastened to the tray by means of suitable closing means such as clips or the like) and the desired seal is ensured due to a seal positioned between the two elements so that the tray-cover system is adequately isolated from the external environment, where the users of the housing operate, thereby avoiding contaminations both of the housing towards the inside of the cage, and from the inside of the cage towards the housing or external environment.

It indeed is to be considered that in most cases, the housing relates to “clean” animals, in particular called “SPF”, specific pathogen free, wherein the volume and the inner surfaces of the cage in the case of “clean” animals are kept and are considered “clean”, while everything outside the cage, including the external surface of the cage itself, is considered potentially “dirty” and contaminated.

To the contrary, the opposite concept applies in the case of potentially contaminated animals, in particular from a microbiological viewpoint, wherein t everything inside the cage is considered “dirty” and therefore potentially contaminating for the outside, including the operators.

In both cases, however, the primary need arises to avoid the exchanges and/or mixtures (in particular microbiological contaminations) of what is confined inside the cage and what is outside thereof, thereby maintaining the concept of aseptic conditions.

Therefore, it is apparent that all the operations requesting opening the cage, and in particular removing the cover, are to be carried out according to methods such as to avert the aforesaid mixtures and therefore any contamination of the cage and of the accessories therein and of the animals, but also of the external environment and in particular, of the operators. Such operations comprise for example, but not exclusively, changing the cage (in order to put the animal in a new tray with clean and dry litter, new food and sometimes fresh water), taking and relocating the animals according to the gender and before they reach reproduction maturity, wherein removing the cover is required also in the case of “procedures”, such as for example, specific experiments, weighing the animals, injecting and/or taking samples of biological liquids, diagnostics, health check-ups, surgical interventions, etc., and wherein according to the most common methods implemented, the aforesaid operations are carried out in controlled atmosphere in change or microbiological safety cabinets.

Said microbiological safety cabinets, also more simply referred to as cage changes, essentially comprise a work surface struck by a flow of barrier gas, in particular of barrier air, which is perpendicular to the work surface, and possibly by a further flow substantially parallel to the work surface, said work surface being closed on two/three sides by means of fixed walls and accessible from one side at which there is prepared a vertical sliding window, wherein, due to the calibration of the one or more barrier flows taken from peripheral slits provided along the outer perimeter of the work surface, an attempt is made to obtain the desired protection and to avert the aforesaid contaminations of animals and/or cages and/or components and/or operator. In practice, the air walls prevent that which is outside the work surface from contaminating the material inside, and that which is inside and potentially contaminated from being outlet from the laminar flow system and reaching operators and environment.

However, the cages of known type complicate the operations summarized above, even compromising the effectiveness and/or reliability thereof.

Indeed, each of the operations summarized above necessarily requires handling the cover which is in particular to be first removed from the seat thereof on the tray, then positioned on the work surface (generally beside trays or in rear position, paying attention that the internal surfaces do not to come into contact with the work surface or other instruments resting thereon), and finally gripped (ensuring not to touch the inner surface thereof), removing it from the position thereof on the work surface and relocating it in the seat thereof above the tray, thereby reclosing the cage.

However, handling the cover results in a series of drawbacks, essentially due to the limited space on the work surface.

For example, when the cage is changed, both the “dirty” cage, with the animals and the used litter, and the new sterile “clean” cage are necessarily present on the work surface of the cabinet, with the apparent risk of accidental contact between “dirty” components and “sterile” components and that the dirty cover comes into contact with clean components.

In the same way, on occasion of the separation of the genders, there are at least three cages present on the work surface of the cabinet: the original “dirty” one where there is contained the litter and at least two “clean” cages at the sides, each designed to receive the animals of one or the other gender; clearly the risk of contact between dirty components and clean components, in particular between the dirty cover and clean components, is increased here in consideration of the increased number of components to be arranged on the work surface.

In consideration of that disclosed above, the problems and/or drawbacks encountered in handling or managing the cages according to the prior art, in particular the covers of the cages according to the prior art, may be classified in the following groups.

Concerning the risks under item 1), same are at least partly due to the fact that, for example, the hands of the operator may accidentally come into contact with the internal parts of the cover during each of the three handling steps described above. Moreover, when the cover is placed on the work surface, the internal parts thereof may touch potentially contaminated parts such as external parts of the cage itself, the work surface, containers, potentially contaminated test tubes or bottles present within the laminar flow. Finally, it is worth noting that such operations become difficult by the obligation—or at least the opportunity—for the operators to wear gloves, which decrease the friction and sensitivity of the operator's hands, by the minimal spaces inside of which the protection is ensured, and also by the front safety glass which certainly limits the freedom of movement of the arms.

Concerning the risks under item 2), it is worth noting that while the risk in housing generally is associated with the contamination of the animals by pathogens introduced by the operators or already present in the rooms of the housings, the same potential problems described above could result in the contamination of the operators and of the surrounding environment by animals that might host microbiological agents.

Concerning the risks under item 3), it is worth noting that as described above, the restricted area of the work surface often is crowded or occupied because, in addition to the trays being changed, there may be present a plurality of tools useful for the operations, such as containers for disinfectant and/or for the food, bottles for the water, test tubes, cups for microbiological screening, etc.

Such objects are to be carefully positioned inside the sterile area because if they are even briefly positioned outside during the handling and then used, they themselves could become contaminated or contaminate the environment; moreover, such objects may not be positioned along the perimeter of the laminar flow area because by obstructing the air intakes, they could nullify the protection normally ensured by the sterile flow curtain.

Therefore, the risk of human errors which may compromise the required sterility is high.

Concerning the risks under item 4, it is worth noting that even hundreds of cages are changed by a single operator every day in a housing facility: such a procedure results in the repetition of the same movements mainly by the wrist, fingers, elbow and shoulder of the animal care takers, such as opening the cover, positioning it on the work surface generally beside the tray and successively closing it, which result in a rotation of the wrist and of the hand by at least 180 degrees, first in one direction and then in the other. It is known that pathologies such as that of carpal tunnel may affect such operators, also due to these movements.

Finally, concerning the risks under item 5, it is to be noted that regardless of the system and the brand of cage used, no clear procedure for accessing the IVCs exists to date: each facility implements standard operations which tend to minimize the above-described risks, but there is no optimized process recommended by the suppliers because there is no system that simplifies, rationalizes and increases the safety and repeatability of such an operation.

In an attempt to overcome the drawbacks described above and therefore to reduce in particular the risks according to items 1) to 5), support devices have recently been proposed called “top holders”, for supporting the cover (top) of the cage when the same is removed from the tray. In use, said supports are in particular positioned on the work surface of the change cabinet and when the cover is removed from the tray, same is positioned on one of them. Therefore, said supports at least partly facilitate the task of the operator, who knows where to position the cover; moreover, they limit the risk of the (dirty) inner surface of the cover coming into contact with clean components and/or being touched by the operator's hands.

However, although the top holders can be appreciated for the aforesaid reasons, they nevertheless have various drawbacks and do not provide a significant and complete solution to the problems disclosed above.

Indeed, also the top holder type systems present on the market are themselves to be positioned in fixed position on the already restricted work surface, thus occupying a portion thereof and restraining the handling of the cages.

Moreover, being placed externally to the cage on the sides or in rear position, they require an even larger handling space for the operator when they are opened and closed, with respect to that available in the absence thereof.

Therefore, it is the main object of the present invention to overcome or at least minimize the problems summarized above and encountered in the prior art.

In particular, it is a first object of the present invention to provide a solution which allows the facilitated handling of the cover of a cage for laboratory animals, thus limiting the risks of contamination. In detail, it is an object of the present invention to propose a solution which allows repositioning the cover by means of operations that are quick, safe and simple to be carried out. In greater detail, it is an object of the present invention to propose a solution which allows the aforesaid repositioning of the cover but at the same time does not complicate the operations of removing the cover, if desired and/or required.

In consideration both of the drawbacks encountered in the prior art and of the pre-set objects or goals, the object of the present invention according to a first embodiment is a cage for housing laboratory animals, said cage comprising a tray and a cover which can be removed and switched between a first closing position, in which it is positioned on said tray, thus stopping the access to the internal space delimited by said tray, and a second opening position in which said internal space may be accessed, when said cover comprises constraining means, when with the cover in said first closing position, said constraining means do not engage said tray, when contrarily, in said second opening position said constraining means engage a portion of said tray, and when said second position of said cover with respect to said tray is defined by the mutual engagement of said constraining means and said portion of said tray.

According to one embodiment, said constraining means are conformed in such a way that when said cover is in said second opening position, at least one portion of said cover is positioned adjacent to a side wall of the tray, and said cover is substantially parallel to said side wall of said tray.

According to one embodiment, said constraining means are conformed in such a way that when said cover is in said second opening position and said tray is resting on a plane, said cover is raised in respect to said plane.

According to one embodiment, said constraining means comprise at least one hook rigidly constrained to said cover and conformed so as to define a housing and engagement seat, when with said cover in said second opening position said at least one portion of said tray engaged by said constraining means is at least partially housed in said housing and engagement seat defined by said at least one hook.

According to one embodiment, said at least one portion of said tray at least partially housed in said housing and engagement seat defined by said at least one hook, is represented by a portion of a side wall of said tray.

According to one embodiment, said at least one portion of said tray at least partially housed in said housing and engagement seat defined by said at least one hook, is represented by an end portion of a side wall of said tray close to the upper edge of said side wall.

According to one embodiment, said at least one portion of said tray at least partially housed in said housing and engagement seat defined by said at least one hook, is represented by a portion of a side wall of said tray which extends from said side wall outwards from said tray.

According to one embodiment, said cover comprises a main, substantially flat portion, when said at least one hook extends from the inner surface of said main portion facing the inside of said tray with said cover in said first closing position.

According to one embodiment, said cover comprises a main, substantially flat portion and a side wall joined to said substantially flat portion, when said at least one hook extends from said side wall of said cover.

According to one embodiment, said constraining means comprise two of said hooks.

According to one embodiment, said cage comprises at least one trough designed in use to be placed inside said cage.

According to one embodiment, said cover defines a depression adapted to at least partially house a container for liquids, for example drinking water.

According to one embodiment, said cage is of the ventilated type, when said cover comprises means for inletting ventilated air into said cage.

Possible further embodiments of the present invention are defined in the claims.

The present invention is particularly applicable in the field of housing laboratory animals, this being the reason why the present invention is described below with particular reference to the applications thereof in the field of housing animals.

It is in any case worth noting that the possible applications of the present invention are not limited to those described below. Contrarily, the present invention is conveniently applied in all those cases in which there is a need to optimize the opening of a container including a main containment portion and a cover which can be switched between a first closing position, in which it stops the access to the inside of said main portion, and a second opening position, in which contrarily the inside of said main portion is allowed and/or possible.

The cage according to one embodiment of the present invention is identified as a whole inwith numeral; as depicted, the cagecomprises a traydesigned to contain the litter for animals to be housed (possibly together with other accessories such as for example, troughin), wherein the traysubstantially defines the space available to the animals. Again as depicted, the cagecomprises a closing coveradapted to be positioned on tray(and possibly fixed thereto by means of fastening means not shown) in the closing position in(in which it stops the animals from leaving and also access to the inside of tray) and to be removed from tray, for example when there is a need for an operator to access the inside of trayand/or when there is a need to carry out the operations summarized above, such as for example, changing the litter or similar operations. In detail, as depicted, trayhas a box-like shape (rectangular in the non-limiting example depicted in the drawings) and comprises a substantially flat bottomand four opposed two-by-two side wallsjoined to one another and joined to bottom(extending from bottom) to define an internal spaceof tray. For the sake of conciseness, reference is indifferently made below to a single side wallor also to the overall side wall, as mentioned formed by the four opposed two-by-two side walls. Covercomprises an actual main cover portioncomprising at least a substantially flat portion, from which a wall or side edge or edgeguardextends in substantially transverse direction (substantially perpendicularly to the flat portion of cover). The side edgecomprises a first portionwhich is arranged around the side wallsof trayin the closing position and is joined to a second portionwhich is arranged on the upper edge of the side wallsof trayin the closing position. The second portionis substantially parallel to the substantially flat portion of the main portionof cover. The side edgealso comprises a third portionwhich is joined to the second portionand to the main portionof cover. The third portionof the side edgeis arranged above the internal spaceof trayin the closing position. Coveralso comprises one or more tray seats, a grid, a depressionfor housing and positioning a containerfor drinking beverages, and also air intakesfor introducing and discharging ventilated and/or forced air into and from cage, respectively. In any case, the air intakes, as well as the gridand the aforesaid depression, are not essential for the objects of the present invention and therefore a detailed description thereof is omitted for the sake of conciseness. The tray seatsof the coverofare formed in the side edge, in particular in the second portionand the third portionof the side edge. The coverofis similar to the cover ofbut does not comprise tray seats.

Concerning the troughin, according to methods which are essentially known and therefore are not described in detail, it is designed to be placed in cage, for example as depicted in, and is conformed so as to contain food and make it available to the animals, in particular so that the food does not come into contact with the litter. Troughis not essential either for the objects of the present invention. Troughcomprises at least one trough seat,, in particular a recess formed on at least one edge of trough, whose function will be described below.

Again as anticipated, the cage according to the present invention comprises peculiarities aiming to optimize the handling of cover; said peculiarities are described below with reference to, in which component and/or characteristic parts of cageaccording to the present invention described above with reference to other drawings, are identified by the same reference numerals.

Numeralinidentifies constraining means as a whole, adapted to allow the facilitated positioning of coverin an opening position different from the closing position in, in which access to the internal spaceof traymay in particular be possible. Said constraining meansessentially comprise a pair of substantially identical hooks, wherein again for conciseness reasons, a detailed description will be given below of one hookalone.